<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>响应式图片</title>
    <link rel="stylesheet" href="css/bootstrap.min.css">
   
</head>
<body>
<div class="container">
    
    <img src="img/1.webp" alt="" class="hidden-xs img-responsive"><!-- 大于768px -->
    <img src="img/3.webp" alt="" class="visible-xs img-responsive"><!-- 小于768px -->

</div>
</body>
</html>